scholarly journals In Vitro Susceptibility of Mycobacterium abscessus and Mycobacterium fortuitum Isolates to 30 Antibiotics

2018 ◽  
Vol 2018 ◽  
pp. 1-10 ◽  
Author(s):  
Yaojie Shen ◽  
Xuyang Wang ◽  
Jialin Jin ◽  
Jing Wu ◽  
Xuelian Zhang ◽  
...  
Keyword(s):  
Public Health Problem ◽  
Drug Susceptibility ◽  
Mycobacterium Abscessus ◽  
Mycobacterium Fortuitum ◽  
In Vitro Susceptibility ◽  
Antitubercular Drugs ◽  
Microdilution Method ◽  
Susceptibility Tests ◽  
Susceptibility Profiles

Objective. Nontuberculous mycobacteria (NTM) cause various diseases in humans and animals. Recently, the prevalence of NTM-related disease has been on the rise, becoming an emerging public health problem. The aim of this study was to determine the antibiotic susceptibility profiles of clinical isolates of Mycobacterium abscessus and Mycobacterium fortuitum. Methods. We performed susceptibility tests on 37 clinical NTM isolates to 30 antibiotics with the microdilution method recommended by the Clinical and Laboratory Standards Institute. Results. Both M. abscessus and M. fortuitum were highly resistant to antitubercular drugs such as isoniazid, rifampin, ethambutol, clofazimine, ethionamide, and rifabutin. M. abscessus showed the lowest resistant rates to cefoxitin (10%), azithromycin (10%), amikacin (10%), and clarithromycin (20%) and very high resistant to sulfamethoxazole, vancomycin, oxacillin, clindamycin, and all fluoroquinolones. M. fortuitum showed low resistance to tigecycline (0%), tetracycline (0%), cefmetazole (12%), imipenem (12%), linezolid (18%), and the aminoglycosides amikacin (0%), tobramycin (0%), neomycin (0%), and gentamycin (24%). Conclusion. Amikacin, cefoxitin, and azithromycin have the highest in vitro activity against M. abscessus. Isolates of M. fortuitum need to be individually evaluated for drug susceptibility before choosing an effective antimicrobial regimen for treatment of infections.

Antifungal susceptibility of bloodstream yeasts isolated at a public children’s hospital in Brazil: comparison of the Etest® and the AFST–EUCAST microdilution method

2007 ◽  
Vol 53 (12) ◽  
pp. 1300-1306 ◽  
Author(s):  
Flávia E. Matsumoto ◽  
Amanda L.T. Dias ◽  
Márcia S.C. Melhem ◽  
Maria W. Szeszs ◽  
Marcos E. Auler ◽  
...  
Keyword(s):  
Amphotericin B ◽  
Susceptibility Testing ◽  
Antifungal Susceptibility ◽  
Candida Spp ◽  
In Vitro Susceptibility ◽  
Microdilution Method ◽  
Susceptibility Tests ◽  
Susceptibility Profiles

This study compared the minimum inhibitory concentration (MIC) results from the proposed standard methods of the Antifungal Susceptibility Testing Subcommittee of the European Committee on Antibiotic Susceptibility Testing (AFST–EUCAST) with the commercial system Etest® in the evaluation of susceptibility to flucytosine, fluconazole, itraconazole, voriconazole, and amphotericin B of 136 Candida spp. isolated from the blood of hospitalized children. The results presented a greater agreement among Etest® MICs ±2 log2 dilutions of AFST–EUCAST for fluconazole (98.1% and 96.3%) and voriconazole (100% and 100%) for Candida albicans and Candida parapsilosis . For Candida glabrata , the agreement was greater only for fluconazole (81.8%) and voriconazole (100%). For amphotericin B, the agreement between the methods was low for all species. The agreement percentage among the Etest® and AFST–EUCAST susceptibility profiles was high according to the MIC breakpoints recommended by the M27-A2 protocol for the majority of the yeasts, except for fluconazole and itraconazole against Candida tropicalis and for itraconazole against C. glabrata and Candida krusei . According to both methodologies, a great number of Candida spp. isolates showed an in vitro susceptibility to all evaluated antifungal agents. Overall, both procedures can be reliable techniques for susceptibility tests of yeasts, but the assessment of interlaboratory agreement and correlation of MICs by different methods with in vivo response are of great importance.

scholarly journals Impact of susceptibility to injectable antibiotics on the treatment outcomes of Mycobacterium abscessus pulmonary disease

2021 ◽  
Author(s):  
Youngmok Park ◽  
Yea Eun Park ◽  
Byung Woo Jhun ◽  
Jimyung Park ◽  
Nakwon Kwak ◽  
...  
Keyword(s):  
Treatment Outcomes ◽  
Pulmonary Disease ◽  
Drug Susceptibility ◽  
Mycobacterium Abscessus ◽  
Beta Lactams ◽  
In Vitro Susceptibility ◽  
Referral Hospitals ◽  
Microbiological Cure ◽  
Culture Conversion

Abstract Objectives Current guidelines recommend a susceptibility-based regimen for Mycobacterium abscessus subspecies abscessus pulmonary disease (MAB-PD), but the evidence is weak. We aimed to investigate the association between treatment outcomes and in vitro drug susceptibility to injectable antibiotics in MAB-PD patients. Methods We enrolled MAB-PD patients treated with intravenous amikacin and beta-lactams for ≥4 weeks at four referral hospitals in Seoul, South Korea. Culture conversion and microbiological cure at one year were evaluated based on susceptibility to injectable antibiotics among patients treated with those antibiotics for ≥ 2 weeks. Results A total of 82 patients were analysed. The mean age was 58.7 years, and 65.9% were women. Sputum culture conversion and microbiological cure were achieved in 52.4% and 41.5% of patients, respectively. Amikacin was the most common agent to which the M. abscessus subspecies abscessus isolates were susceptible (81.7%); 9.8% and 24.0% of the isolates were resistant to cefoxitin and imipenem, respectively. The clarithromycin-inducible resistance (IR) group (n = 65) had a lower microbiological cure rate than the clarithromycin-susceptible group (35.4% vs. 64.7%). The treatment outcomes appeared to be similar regardless of in vitro susceptibility results with regard to intravenous amikacin, cefoxitin, imipenem, and moxifloxacin. In the subgroup analysis of the clarithromycin-IR group, the treatment outcomes did not differ according to antibiotic susceptibility. Conclusions We did not find evidence supporting the use of susceptibility-based treatment with intravenous amikacin and beta-lactams in patients with MAB-PD. Further research would be required.

Prolonged Pneumococcal Meningitis Due to an Organism With Increased Resistance to Penicillin

PEDIATRICS ◽  
1976 ◽  
Vol 58 (3) ◽  
pp. 378-381 ◽  
Author(s):  
Abel Paredes ◽  
Larry H. Taber ◽  
Martha D. Yow ◽  
Dorothy Clark ◽  
William Nathan
Keyword(s):  
Case Report ◽  
Streptococcus Pneumoniae ◽  
Pneumococcal Meningitis ◽  
Pneumococcal Infections ◽  
In Vitro Susceptibility ◽  
Focus Of Infection ◽  
Resistance To Penicillin ◽  
Penicillin Treatment ◽  
Susceptibility Tests

For more than 30 years, penicillin has been the agent of choice for pneumococcal infections. During this time the majority of strains of Streptococcus pneumoniae have been highly susceptible to penicillin. However, during the last ten years there have been sporadic reports of pneumococci with increased resistance to penicillin. The case report of an 18-month-old white boy with meningitis due to a strain of S. pneumoniae with increased resistance to penicillin is presented. The MIC of the organism to penicillin was 0.2µg/ml and the MBC 0.39µg/ml. The patient had normal immunity and no demonstrable sequestered focus of infection but failed to respond to appropriate doses of intravenous penicillin. Treatment with chloramphenicol caused a dramatic bacteriologic and clinical response. This experience reemphasizes the existence of pneumococcal strains of intermediate penicillin sensitivity and the importance of in vitro susceptibility tests.

Assessment of Laboratory Performance With Streptococcus pneumoniae Antimicrobial Susceptibility Testing in the United States

1999 ◽  
Vol 123 (4) ◽  
pp. 285-289 ◽  
Author(s):  
Gary V. Doern ◽  
Angela B. Brueggemann ◽  
Michael A. Pfaller ◽  
Ronald N. Jones
Keyword(s):  
United States ◽  
Streptococcus Pneumoniae ◽  
Antimicrobial Agents ◽  
Susceptibility Testing ◽  
Clinical Laboratory ◽  
The United States ◽  
National Committee ◽  
In Vitro Susceptibility ◽  
Susceptibility Tests

Abstract Objective.—To assess the performance of clinical microbiology laboratories in the United States when conducting in vitro susceptibility tests with Streptococcus pneumoniae. Methods.—The results of a nationwide College of American Pathologists Proficiency Survey test sample, in which susceptibility testing of an isolate of S pneumoniae was performed, were assessed with respect to precision and accuracy. Results.—Wide variability was noted among participating laboratories with both minimum inhibitory concentration procedures and disk diffusion susceptibility tests when both methods were applied to S pneumoniae. Despite this high degree of variation, categorical interpretive errors were uncommon. Numerous laboratories reported results for antimicrobial agents that are not recommended by the National Committee for Clinical Laboratory Standards for tests with S pneumoniae. Conclusions.—Current susceptibility testing practices with S pneumoniae in the United States indicate limited precision and a tendency for laboratories to test and report results obtained with antimicrobial agents of questionable therapeutic value against this organism. Continued efforts to standardize susceptibility testing of S pneumoniae in the United States are warranted. In addition, modifications of existing interpretive criteria may be necessary.

scholarly journals Recurrent candidaemia in a neonate with Hirschsprung's disease: fluconazole resistance and genetic relatedness of eight Candida tropicalis isolates

2006 ◽  
Vol 55 (4) ◽  
pp. 423-428 ◽  
Author(s):  
Pei Pei Chong ◽  
David Ching-Soo Chieng ◽  
Lee Yean Low ◽  
Asma Hafeez ◽  
Mariana Nor Shamsudin ◽  
...  
Keyword(s):  
Candida Tropicalis ◽  
Hirschsprung's Disease ◽  
Hirschsprung’S Disease ◽  
Genetic Relatedness ◽  
Infectious Agent ◽  
Venous Catheter ◽  
Drug Susceptibility ◽  
Fluconazole Resistant ◽  
Susceptibility Tests

The incidence of candidaemia among immunocompromised patients in Malaysia is increasing at an alarming rate. Isolation of clinical strains that are resistant to fluconazole has also risen markedly. We report here the repeated isolation of Candida tropicalis from the blood of a neonatal patient with Hirschsprung's disease. In vitro fluconazole susceptibility tests of the eight isolates obtained at different time points showed that seven of the isolates were resistant and one isolate was scored as susceptible dose-dependent. Random amplification of polymorphic DNA fingerprinting of the isolates using three primers and subsequent phylogenetic analysis revealed that these isolates were highly similar strains having minor genetic divergence, with a mean pairwise similarity coefficient of 0·893±0·041. The source of the infectious agent was thought to be the central venous catheter, as culture of its tip produced fluconazole-resistant C. tropicalis. This study demonstrates the utility of applying molecular epidemiology techniques to complement traditional mycological culture and drug susceptibility tests for accurate and appropriate management of recurrent candidaemia and highlights the need for newer antifungals that can combat the emergence of fluconazole-resistant C. tropicalis strains.

scholarly journals Correlation of In Vitro Activity, Serum Levels, and In Vivo Efficacy of Posaconazole against Rhizopus microsporus in a Murine Disseminated Infection

2009 ◽  
Vol 53 (12) ◽  
pp. 5022-5025 ◽  
Author(s):  
M. Mar Rodríguez ◽  
F. Javier Pastor ◽  
Enrique Calvo ◽  
Valentina Salas ◽  
Deanna A. Sutton ◽  
...  
Keyword(s):  
Serum Levels ◽  
Rhizopus Microsporus ◽  
In Vitro Susceptibility ◽  
In Vivo Efficacy ◽  
Susceptibility Data ◽  
Microdilution Method ◽  
Drug Concentrations ◽  
Broth Microdilution Method

ABSTRACT A broth microdilution method was used to evaluate the in vitro activities of seven antifungal agents against 15 clinical strains of Rhizopus microsporus. Amphotericin B (AMB) and posaconazole (POS) were the most active drugs. In a model of disseminated R. microsporus infection in immunosuppressed mice, we studied the efficacy of POS administered once or twice daily against four of the strains previously tested in vitro and compared it with that of liposomal AMB (LAMB). LAMB was the most effective treatment for the two strains with intermediate susceptibility to POS. For the two POS-susceptible strains, LAMB and POS at 20 mg/kg of body weight twice a day orally showed similar efficacies. The in vivo efficacy of POS administered twice a day orally correlated with the in vitro susceptibility data and the serum drug concentrations.

scholarly journals Molecular epidemiology, in vitro susceptibility and exoenzyme screening of Malassezia clinical isolates

2020 ◽  
Vol 69 (3) ◽  
pp. 436-442 ◽  
Author(s):  
Wei Li ◽  
Zi-Wei Zhang ◽  
Yun Luo ◽  
Ni Liang ◽  
Xiao-Xue Pi ◽  
...  
Keyword(s):  
Molecular Epidemiology ◽  
Synergistic Effects ◽  
Extracellular Enzyme ◽  
Drug Susceptibility ◽  
Clinical Isolates ◽  
Sequencing Analysis ◽  
In Vitro Susceptibility ◽  
Major Species ◽  
Malassezia Globosa

Introduction. Malassezia folliculitis (MF) and pityriasis versicolor (PV) are common dermatoses caused by Malassezia species. Their molecular epidemiology, drug susceptibility and exoenzymes are rarely reported in China. Aim. To investigate the molecular epidemiology, drug susceptibility and enzymatic profile of Malassezia clinical isolates. Methodology. Malassezia strains were recovered from MF and PV patients and healthy subjects (HS) and identified by sequencing analysis. The minimum inhibitory concentrations (MICs) of nine antifungals (posaconazole, voriconazole, itraconazole, fluconazole, ketoconazole, miconazole, bifonazole, terbinafine and caspofungin) and tacrolimus, the interactions between three antifungals (itraconazole, ketoconazole and terbinafine) and tacrolimus, and the extracellular enzyme profile were evaluated using broth and checkerboard microdilution and the Api-Zym system, respectively. Results. Among 392 Malassezia isolates from 729 subjects (289 MF, 218 PV and 222 HS), Malassezia furfur and Malassezia globosa accounted for 67.86 and 18.88 %, respectively. M. furfur was the major species in MF and PV patients and HS. Among 60M. furfur and 50M. globosa strains, the MICs for itraconazole, posaconazole, voriconazole and ketoconazole were <1 μg ml−1. M. furfur was more susceptible to itraconazole, terbinafine and bifonazole but tolerant to miconazole compared with M. globosa (P<0.05). Synergistic effects between terbinafine and itraconazole or between tacrolimus and itraconazole, ketoconazole or terbinafine occurred in 6, 7, 6 and 9 out of 37 strains, respectively. Phosphatases, lipases and proteases were mainly secreted in 51 isolates. Conclusions. Itraconazole, posaconazole, voriconazole and ketoconazole are theagents against which there is greatest susceptibility. Synergistic effects between terbinafine and itraconazole or tacrolimas and antifungals may be irrelevant to clinical application. Overproduction of lipases could enhance the skin inhabitation of M. furfur.

LABORATORY ASPECTS OF ANTIBIOTIC THERAPY

PEDIATRICS ◽  
1951 ◽  
Vol 8 (3) ◽  
pp. 406-412
Author(s):  
EARLE H. SPAULDING
Keyword(s):  
Antibiotic Therapy ◽  
Single Species ◽  
Clinical Results ◽  
Bacterial Strains ◽  
In Vitro Susceptibility ◽  
Bacterial Cultures ◽  
Susceptibility Tests ◽  
And Control ◽  
Susceptibility Patterns

Bacterial strains within a single species exhibit highly specific susceptibility patterns when tested with the several antibiotics currently available. Because in vitro susceptibility tests constitute the only certain method for predicting clinical response, the bacteriology laboratory is playing an expanding part in the choice and control of antibiotic therapy. Although there is no need for bacteriologic studies in the vast majority of infections, they are sometimes essential to the successful management of severe acute, refractory and relapsing infections. The correlation between laboratory and clinical results is good providing allowances are made for certain factors discussed in this paper. Antibiotic susceptibility tests are entirely practical and should be used routinely in all laboratories which do bacterial cultures.

scholarly journals 1350. Clofazimine as an Oral Companion Drug for Treatment of Mycobacterium abscessus complex Infections

2019 ◽  
Vol 6 (Supplement_2) ◽  
pp. S488-S489
Author(s):  
Joy Yong ◽  
Ka Lip Chew ◽  
Paul Tambyah
Keyword(s):  
Active Agent ◽  
Liver Function Tests ◽  
Mycobacterium Abscessus ◽  
Prolonged Treatment ◽  
Attractive Alternative ◽  
In Vitro Susceptibility ◽  
Treatment Regimens ◽  
Drug Intolerance ◽  
Mycobacterium Abscessus Complex

Abstract Background Infections caused by the multi-drug-resistant Mycobacterium abscessus complex (MabsC) are challenging to treat and often require multiple antimicrobials for a prolonged treatment course and still have poor outcomes. Clofazimine, an oral anti-leprosy drug, has demonstrated good in vitro susceptibility and is being increasingly employed in treatment regimens for MabsC infections. We performed a drug-use-evaluation of clofazimine in the treatment of MabsC infections. Methods A retrospective review was performed for all patients with MabsC infections treated with clofazimine-containing regimens from January 2014 to June 2017. Results Twenty-nine patients were included. Twelve patients had pulmonary MabsC infections and seventeen had extrapulmonary infections. All isolates had clofazimine minimum-inhibitory-concentration of ≤0.5 mg/L as tested by broth microdilution. Clofazimine was prescribed at initiation of therapy in 31.0% (9/29), as a companion drug during maintenance therapy after initial intravenous therapy in 44.8% (13/29) and as part of salvage therapy due to disease progression or drug intolerance in 24.1% (7/29) of patients. Dosing of clofazimine for the pediatric patients was prescribed at 1–2 mg/kg/day while the adult patients received a range of 50–200 mg/day. Clofazimine was given for a median duration of 148.5 days (range: 14–1212) and most commonly in combination with clarithromycin (82.8%), amikacin (58.6%), and cefoxitin (24.1%). Twelve patients had documented adverse reactions attributable to clofazimine: skin hyperpigmentation (66.7%), abnormal liver function tests (16.7%), and gastrointestinal disturbance (16.7%). Table 1 describes the patients who had clofazimine ceased due to an adverse effect. Nine patients with pulmonary MabsC infections and 16 with extrapulmonary MabsC infections had documented improvement in symptoms. Conclusion Clofazimine as a companion drug in the treatment of MabsC infections was reasonably tolerated over a prolonged period of time. Its availability as an oral active agent makes it an attractive alternative to IV companion drugs and potentially improves compliance to the protracted treatment courses for patients with MabsC infections. Disclosures All authors: No reported disclosures.

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